The present invention relates to a device for permanently closing off fluid passages formed in a housing.
Arrangements for permanently closing off fluid passages in hydraulic and pneumatic connectors and housings find many applications and hence are required in large quantities. Closing devices of the above-mentioned type are designed both as force-locking and form-locking elements. Screw-type, bayonet-type and press-type closing arrangements are generally known and widely employed which, admittedly, permit a satisfactory closure of the fluid passages. However, these devices entail disadvantages due to their complicated construction and/or assembly.
For instance, it is known from the illustration of German published patent application DE-OS 37 29 216 to block a fluid passage in a valve block by simply press fitting of a ball into an enlarged portion of the passage, and thereafter caulking the ball in place by upsetting of the passage wall which expedient is reliable and low in cost. This means of closing off a passage has the shortcoming that material is abraded by contact of surfaces of the ball with the surface defining the fluid passage, particularly for relatively soft valve block material during the press fitting. The abraded particles and chips can get into the fluid passage. In consequence of this undesirable effect, thorough rinsing operations are needed in order to eliminate the particles to safeguard the operability of solenoid valves or other sensitive components in the valve block assembly in later use.
Admittedly, it is already known to use so-called "king expanders", wherein a sleeve-shaped supporting body provided with claws is first inserted into the passage to be closed off, a ball is thereafter pressed into the supporting body in order to accomplish the necessary retaining force by expanding the supporting body. However, this closure mechanism still requires a significant assembly effort, and there is still some risk of abrasion particles entering the fluid passages. Also, the manufacturing costs are not minimized. Thus, there is a need for a particularly simple and absolutely reliable closing device.
Therefore, it is an object of the present invention to devise a closing arrangement which lends itself to ease of manufacture and absolutely reliably closes off a fluid passage with minimal mounting effort and without any possibility of releasing abrasion particles into the fluid passage.